– Coal ash releases in the Neuse River have caused arsenic levels to be nearly 18 times higher than the state safety standard for drinking water, two environmental organizations said Friday.

The Upper Neuse Riverkeeper and the Waterkeeper Alliance said a coal ash spill at Duke Energy’s retired H.F. Lee Plant in Goldsboro is the source of the arsenic contamination in the river. The organizations said they also found elevated levels of lead and other heavy metals in lab analysis conducted by Pace Analytical in Raleigh.

Duke Energy strongly disputed the activists’ findings, saying its own lab tests show the Neuse River is not contaminated by flooding from Hurricane Florence. Duke further said the Riverkeeper activists are fomenting fear to increase public pressure to haul away all coal ash, even from locations where the waste is not posing a public health risk.

“The Riverkeeper’s data is irrelevant to drinking water safety, and their continued attempts to misinform are most unfortunate given the devastation many in this community are facing from the hurricane,” Duke Energy spokeswoman Erin Culbert said in an e-mail.

One reason for the disparity in the lab results from Charlotte-based Duke and the activists is that they took water samples in different locations of the Neuse River. The North Carolina Department of Environmental Quality has also taken water samples and expects to issue its lab results on Neuse River water quality Friday afternoon.

The environmental activist groups said that the arsenic standard for drinking water supply and fish consumption is 10 micrograms per liter, but water sampled directly over the flooded coal ash impoundments measured at 186 micrograms per liter.

“We sampled where the spills were occurring,” said Upper Neuse Riverkeeper Matt Starr by phone. “The important thing to know is what is going into the river. Those coal ash ponds were underwater for days.”

Duke said it has found less than 1 microgram per liter on every day but one, and said there is no evidence that coal ash is contaminating the Neuse River. Duke tested the water some distance from the ash storage sites.

“Test results from the river continue to show very little difference between the quality upstream of the H.F. Lee Plant and downstream of the plant,” Culbert said.

Duke had previously acknowledged that flooding at the Goldsboro plant had spilled “a small amount” of ash.

Scientists said Thursday that Duke’s testing on the Cape Fear was not sufficient because Duke was testing only surface water whereas it should also be testing river-bottom sediments for heavy metals that have settled.

Coal ash is a byproduct of burning coal to make electricity. It is not categorized as a hazardous waste by the Environmental Protection Agency but it contains elements such as arsenic, selenium and mercury that can cause cancer and reproductive problems from long-term exposure at elevated levels.